Le dosage des séromuco?des dans la cardite rhumatismale: (Etude de 120 cas)

Seromucoid values were determined in 120 patients with rheumatic carditis, aged 5 to 20 years, who were in the acute, subacute or chronic phase of the disease. The following results were obtained: (1) Seromucoid values were elevated in all 32 of the acute cases and remained above normal as long as rheumatic activity was present. (2) Seromucoid values were unaffected by cortisone therapy, unlike the sedimentation rate and the level of C-reactive protein. (3) Greater values for seromucoid were found in severe cases.This study suggests that seromucoid determination is a useful method for following rheumatic activity and may be of value in assessing the severity of the disease.     

On the mechanisms of cadmium stress alleviation in Medicago truncatula by arbuscular mycorrhizal symbiosis: A root proteomic study

The arbuscular mycorrhizal (AM) symbiosis belongs to the strategies plants have developed to cope with adverse environmental conditions including contamination by heavy metals such as cadmium (Cd). In the present work, we report on the protective effect conferred by AM symbiosis to the model legume Medicago truncatula grown in presence of Cd, and on the 2‐D‐based proteomic approach further used to compare the proteomes of M. truncatula roots either colonised or not with the AM fungus Glomus intraradices in Cd‐free and Cd‐contaminated substrates. The results indicated that at the proteome level, 9 out of the 15 cadmium‐induced changes in nonmycorrhizal roots were absent or inverse in those Cd‐treated and colonized by G. intraradices, including the G. intraradices‐dependent down‐accumulation of Cd stress‐responsive proteins. Out of the twenty‐six mycorrhiza‐related proteins that were identified, only six displayed changes in abundance upon Cd exposure, suggesting that part of the symbiotic program, which displays low sensitivity to Cd, may be recruited to counteract Cd toxicity through the mycorrhiza‐dependent synthesis of proteins having functions putatively involved in alleviating oxidative damages, including a cyclophilin, a guanine nucleotide‐binding protein, an ubiquitin carboxyl‐terminal hydrolase, a thiazole biosynthetic enzyme, an annexin, a glutathione S‐transferase (GST)‐like protein, and a S‐adenosylmethionine (SAM) synthase.     

Recombinant Surface Proteomics as a Tool to Analyze Humoral Immune Responses in Bovines Infected by Mycoplasma mycoides Subsp. mycoides Small Colony Type

A systematic approach to characterize the surface proteome of Mycoplasma mycoides subspecies mycoides small colony type (M. mycoides SC), the causative agent of contagious bovine pleuropneumonia (CBPP) in cattle, is presented. Humoral immune responses in 242 CBPP-affected cattle and controls were monitored against one-third of the surface proteins of M. mycoides SC in a high throughput magnetic bead-based assay. Initially, 64 surface proteins were selected from the genome sequence of M. mycoides SC and expressed as recombinant proteins in Escherichia coli. Binding of antibodies to each individual protein could then be analyzed simultaneously in minute sample volumes with the Luminex suspension array technology. The assay was optimized on Namibian CBPP-positive sera and Swedish negative controls to allow detection and 20-fold mean signal separation between CBPP-positive and -negative sera. Signals were proven to be protein-specific by inhibition experiments, and results agreed with Western blot experiments. The potential of the assay to monitor IgG, IgM, and IgA responses over time was shown in a proof-of-concept study with 116 sera from eight animals in a CBPP vaccine study. In conclusion, a toolbox with recombinant proteins and a flexible suspension array assay that allows multiplex analysis of humoral immune responses to M. mycoides SC has been created.Mycoplasma mycoides subsp. mycoides small colony type (M. mycoides SC)¹ is the causative agent of contagious bovine pleuropneumonia (CBPP), a severe respiratory disease in cattle. It is a disease requiring official declaration to the World Organization for Animal Health (OIE) and that causes vast problems in Africa with severe socioeconomic consequences (1, 2). In 2006, 15 African countries reported 186 outbreaks of CBPP to the OIE. CBPP was eradicated from Europe in the beginning of the 20th century (3) but has reemerged in every decade since (4). Eradication was largely facilitated by slaughtering infected herds, which is still considered as the most efficient means of disease control and was successfully performed in Botswana in 1995 (5). However, this campaign was directly correlated to increased malnutrition in children (6) and is also considered to be too expensive for other African countries (2, 7). The use of chemotherapy in CBPP control is a debated subject, has long been discouraged, and is even illegal in some countries (1), mainly because of the risk of creating silent carriers of the disease (8). However, new antibiotics have shown positive effects (9), but extensive vaccinations are still considered the preferred option for prevention and control of CBPP in Africa (2, 10, 11). The vaccines currently in use are based on live attenuated M. mycoides SC strains and have several disadvantages such as short term immunity (12), poor protection as indicated in recent trials (4, 13), and even pathogenicity (13, 14).The two currently available tests for serological diagnosis of CBPP recommended by the OIE, the complement fixation test (15) and a competitive ELISA (16), are based on whole cell M. mycoides SC. For subcellular components of the organism, the genome sequence of M. mycoides SC strain PG1 (17) offers an emerging possibility to improve both diagnostic and therapeutic approaches with selected antigens. However, as for the 10 other Mycoplasma genomes sequenced, the genome sequences per se did not reveal any primary virulence factors common in other bacteria, such as adhesins or toxins (18). The few known molecular mechanisms of pathogenicity were recently reviewed (18) and include five lipoproteins studied in detail: LppA (19, 20), LppB (21), LppC (22) LppQ (23), and Vmm (24). Of these, LppQ has been used to develop an indirect ELISA (25), and Vmm, a variable surface protein, has recently been studied along with five novel putative variable surface proteins as recombinant proteins expressed in Escherichia coli (26). That study demonstrated the feasibility of producing recombinant surface proteins from M. mycoides SC in E. coli and screening for antibodies in sera from CBPP-affected bovines by Western and dot blotting.To explore further the immunogenicity of the M. mycoides SC surface proteome, a platform for multiplexed analysis of proteins using minute serum samples such as bead-based array systems (27) is desirable. One method is available from Luminex Corp. and uses spectrally distinguishable beads (28) to form an array in suspension. The array is analyzed in a flow cytometer-like instrument and can perform up to 100 simultaneous assays in a single reaction well. This platform has recently been used to determine binding specificities to antigens produced in a similar fashion (29) and to profile antibodies in serum toward six antigens of Mycobacterium tuberculosis (30).The aim of this study was to develop a rapid and highly multiplex method for affinity analysis of antibody levels in serum samples from CBPP-affected bovines against recombinant M. mycoides SC surface proteins. To facilitate this, a large set of surface proteins were cloned, expressed in E. coli, and purified. Furthermore, the bead-based assay conditions had to be optimized and verified for detection of immunoglobulin levels in bovine sera. This methodology would enable monitoring and protein-specific characterization of humoral immune responses during CBPP infections. As a secondary aim, the study was expanded to include specific IgG, IgA, and IgM responses in sera from a vaccine study with time series sampling from each animal over 8 months, covering prevaccination and 4 months postinfection.     

Do distantly related parasites rely on the same proximate factors to alter the behaviour of their hosts?

Phylogenetically unrelated parasites often increase the chances of their transmission by inducing similar phenotypic changes in their hosts. However, it is not known whether these convergent strategies rely on the same biochemical precursors. In this paper, we explored such aspects by studying two gammarid species (Gammarus insensibilis and Gammarus pulex; Crustacea: Amphipoda: Gammaridae) serving as intermediate hosts in the life cycle of two distantly related parasites: the trematode, Microphallus papillorobustus and the acanthocephalan, Polymorphus minutus. Both these parasite species are known to manipulate the behaviour of their amphipod hosts, bringing them towards the water surface, where they are preferentially eaten by aquatic birds (definitive hosts). By studying and comparing the brains of infected G. insensibilis and G. pulex with proteomics tools, we have elucidated some of the proximate causes involved in the parasite-induced alterations of host behaviour for each system. Protein identifications suggest that altered physiological compartments in hosts can be similar (e.g. immunoneural connexions) or different (e.g. vision process), and hence specific to the host-parasite association considered. Moreover, proteins required to alter the same physiological compartment can be specific or conversely common in both systems, illustrating in the latter case a molecular convergence in the proximate mechanisms of manipulation.     

Stability of Soybean Recombinant Plastome Over Six Generations

The stability of a plastid transgene has been evaluated in soybean transformants over six generations. These transformants had integrated the aadA selection cassette in the intergenic region between the rps12/7 and trnV genes. Three independent homoplasmic T0 transformation events were selected and ten plants from each event propagated to generation T5 in the absence of selection pressure. No transgene rearrangement nor wild-type plastome were detected in generation T5 by Southern blot analysis. All tested progenies were uniformly resistant to spectinomycin. Therefore, soybean transformants of generations T0 and T5 appear to be genetically and phenotypically identical.     

Human mutation within Per-Arnt-Sim (PAS) domain-containing protein kinase (PASK) causes basal insulin hypersecretion

PAS kinase (PASK) is a glucose-regulated protein kinase involved in the control of pancreatic islet hormone release and insulin sensitivity. We aimed here to identify mutations in the PASK gene that may be associated with young-onset diabetes in humans. We screened 18 diabetic probands with unelucidated maturity-onset diabetes of the young (MODY). We identified two rare nonsynonymous mutations in the PASK gene (p.L1051V and p.G1117E), each of which was found in a single MODY family. Wild type or mutant PASKs were expressed in HEK 293 cells. Kinase activity of the affinity-purified proteins was assayed as autophosphorylation at amino acid Thr307 or against an Ugp1p-derived peptide. Whereas the PASK p.G1117E mutant displayed a ～25% increase with respect to wild type PASK in the extent of autophosphorylation, and a ～2-fold increase in kinase activity toward exogenous substrates, the activity of the p.L1051V mutant was unchanged. Amino acid Gly1117 is located in an α helical region opposing the active site of PASK and may elicit either: (a) a conformational change that increases catalytic efficiency or (b) a diminished inhibitory interaction with the PAS domain. Mouse islets were therefore infected with adenoviruses expressing wild type or mutant PASK and the regulation of insulin secretion was examined. PASK p.G1117E-infected islets displayed a 4-fold decrease in glucose-stimulated (16.7 versus 3 mM) insulin secretion, chiefly reflecting a 4.5-fold increase in insulin release at low glucose. In summary, we have characterized a rare mutation (p.G1117E) in the PASK gene from a young-onset diabetes family, which modulates glucose-stimulated insulin secretion.     

Regenerative Therapeutic Potential of Adipose Stromal Cells in Early Stage Diabetic Retinopathy

Diabetic retinopathy (DR) is the leading cause of blindness in working-age adults. Early stage DR involves inflammation, vascular leakage, apoptosis of vascular cells and neurodegeneration. In this study, we hypothesized that cells derived from the stromal fraction of adipose tissue (ASC) could therapeutically rescue early stage DR features. Streptozotocin (STZ) induced diabetic athymic nude rats received single intravitreal injection of human ASC into one eye and saline into the other eye. Two months post onset of diabetes, administration of ASC significantly improved “b” wave amplitude (as measured by electroretinogram) within 1–3 weeks of injection compared to saline treated diabetic eyes. Subsequently, retinal histopathological evaluation revealed a significant decrease in vascular leakage and apoptotic cells around the retinal vessels in the diabetic eyes that received ASC compared to the eyes that received saline injection. In addition, molecular analyses have shown down-regulation in inflammatory gene expression in diabetic retina that received ASC compared to eyes that received saline. Interestingly, ASC were found to be localized near retinal vessels at higher densities than seen in age matched non-diabetic retina that received ASC. In vitro, ASC displayed sustained proliferation and decreased apoptosis under hyperglycemic stress. In addition, ASC in co-culture with retinal endothelial cells enhance endothelial survival and collaborate to form vascular networks. Taken together, our findings suggest that ASC are able to rescue the neural retina from hyperglycemia-induced degeneration, resulting in importantly improved visual function. Our pre-clinical studies support the translational development of adipose stem cell-based therapy for DR to address both retinal capillary and neurodegeneration.